A controversial proposed anti-terrorism law has been rejected by the upper house of the Indian parliament.

The situation in Gujarat is highly explosive. The government must release all those held under Poto

Congress MP Madhusudhan Mistri

The Prevention of Terrorism Ordinance (Poto) was passed by the lower house earlier this week.

But the BJP-led coalition failed to push it through the upper house where it does not have a majority.

Announced after the 11 September attacks in the United States, the ordinance allows security forces much greater power of arrest, interrogation and detention.

The proposed law would allow security forces to detain suspects for up to 30 days without having to bring them to a court.

Joint session

Police are already able to act on the bill's provisions as, under the Indian constitution, the government can implement laws for a limited period.

However, such bills must eventually win the approval of parliament otherwise they lapse.

A BJP official said on Monday if the bill was defeated in upper house, the government would convene a joint session of the two houses to get the bill passed.

Poto defines as a "terrorist" anyone threatening India's unity as well as causing "terror among people".

However, criticism of the bill has focused on fears that it may be used to target members of minority communities in predominantly Hindu India.

Gujarat violence

Concern has increased since the recent outbreak of violence in the western state of Gujarat, which left more than 700 people dead.

Before Thursday's vote, one of the smaller parties in the governing coalition, the DMK party, told the French news agency that it was looking into reports that Poto had been misused against members of the Muslim community in Gujarat.

Recent attacks strengthened support for new law

And opposition parties in parliament - led by Congress - alleged that those detained under the law in Gujarat do not include prominent Hindu hardliners reportedly involved in orchestrating the violence.

Muslims were targeted by Hindu rioters in revenge for an attack on a train carrying Hindu activists back from the town of Ayodhya, the focus of a dispute over plans to build a temple.

The bill, described as draconian by the opposition, was defeated when it was first placed before the lower house in December.

It was re-issued after an attack on the Indian parliament building by gunmen on 13 December, and appeared to gain support after that incident and an attack on a US cultural centre in Calcutta.